You can take a Y-Cable and connect it to the Line Out pair on the Powertek. You would then run an IC or Sub cable from the singleton end of the Y-Cable to the sub.
Alternatively, Audioquest makes an RCA Splitter (1M/2F) that you could connect in pairs to the Line Out on the Pretek. You would then connect a Y-Cable to one of the F-pairs on the splitters and then connect and IC to the singleton end of the Y-Cable, which would then run to the sub.
On newer Linn Preamps, there are 2 Line Out pairs. I have a Wakonda, and have a Y-Cable connected to one of the Line Out pairs which, in turn, is connected to a sub. The other Line Out pair is connected to an LK85 amp.
Alternatively, Audioquest makes an RCA Splitter (1M/2F) that you could connect in pairs to the Line Out on the Pretek. You would then connect a Y-Cable to one of the F-pairs on the splitters and then connect and IC to the singleton end of the Y-Cable, which would then run to the sub.
On newer Linn Preamps, there are 2 Line Out pairs. I have a Wakonda, and have a Y-Cable connected to one of the Line Out pairs which, in turn, is connected to a sub. The other Line Out pair is connected to an LK85 amp.